Unique nucleocytoplasmic dsDNA and +ssRNA viruses are associated with the dinoflagellate endosymbionts of corals
Unique nucleocytoplasmic dsDNA and +ssRNA viruses are associated with the dinoflagellate endosymbionts of corals
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DOI：
10.1038/ismej.2012.75
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发表时间：
2013-01-01
期刊：
影响因子：
11
通讯作者：
Thurber, Rebecca L. Vega
中科院分区：
文献类型：
--
作者：
Correa, Adrienne M. S.;Welsh, Rory M.;Thurber, Rebecca L. Vega
甲藻（属：共生藻）的居住在石珊瑚是至关重要的建设和持久的热带珊瑚礁。然而，近几十年来，急性和慢性环境压力经常破坏这种共生关系，最终导致珊瑚死亡和珊瑚礁衰退。病毒感染被认为是珊瑚共生藻解离的触发因素;珊瑚相关病毒的多样性和宿主知识对于评估这一假设至关重要。在这里，我们提出了第一个基因组证据与共生藻相关的病毒，基于存在的转录+SS（单链）RNA和DS（双链）DNA病毒样基因的互补DNA病毒组的珊瑚Montastraea cavernosa和表达序列标签（EST）的共生藻文化产生的库。分枝海绵体病毒组含有与甲藻感染+ssRNA异囊藻环甲藻病毒的主要衣壳蛋白相似的不同病毒序列，表明一种高度新颖的甲藻RNA病毒可以感染共生藻。此外，在M.海绵状体病毒在病毒组中鉴定出与真核藻类感染藻DNA病毒高度相似的转录物，并且在两个独立产生的共生藻EST文库中发现了这些序列的同源物。系统发育重建证实，这些成绩单是未描述的核质大DNA病毒（NCLDVs）组的不同成员。基于大量的证据，我们推断这里描述的新型NCLDVs和RNA病毒与珊瑚的藻类内共生体有关。如果此类病毒破坏共生藻，它们可能会影响珊瑚藻共生体的灵活性和/或稳定性，从而影响珊瑚礁的长期健康和复原力。The ISME Journal（2013）7，13-27; doi：10.1038/ismej.2012.75; 2012年7月12日在线发表
The residence of dinoflagellate algae (genus: Symbiodinium) within scleractinian corals is critical to the construction and persistence of tropical reefs. In recent decades, however, acute and chronic environmental stressors have frequently destabilized this symbiosis, ultimately leading to coral mortality and reef decline. Viral infection has been suggested as a trigger of coral-Symbiodinium dissociation; knowledge of the diversity and hosts of coral-associated viruses is critical to evaluating this hypothesis. Here, we present the first genomic evidence of viruses associated with Symbiodinium, based on the presence of transcribed +ss (single-stranded) RNA and ds (double-stranded) DNA virus-like genes in complementary DNA viromes of the coral Montastraea cavernosa and expressed sequence tag (EST) libraries generated from Symbiodinium cultures. The M. cavernosa viromes contained divergent viral sequences similar to the major capsid protein of the dinoflagellate-infecting +ssRNA Heterocapsa circularisquama virus, suggesting a highly novel dinornavirus could infect Symbiodinium. Further, similarities to dsDNA viruses dominated (similar to 69%) eukaryotic viral similarities in the M. cavernosa viromes. Transcripts highly similar to eukaryotic algae-infecting phycodnaviruses were identified in the viromes, and homologs to these sequences were found in two independently generated Symbiodinium EST libraries. Phylogenetic reconstructions substantiate that these transcripts are undescribed and distinct members of the nucleocytoplasmic large DNA virus (NCLDVs) group. Based on a preponderance of evidence, we infer that the novel NCLDVs and RNA virus described here are associated with the algal endosymbionts of corals. If such viruses disrupt Symbiodinium, they are likely to impact the flexibility and/or stability of coral-algal symbioses, and thus long-term reef health and resilience. The ISME Journal (2013) 7, 13-27; doi:10.1038/ismej.2012.75; published online 12 July 2012